#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int x;
int y;

int addtwonum()
{
	extern int x;
	extern int y;

	x = 1;
	y = 2;
	
	return x + y;
}

int main()
{
	int result;
	result = addtwonum();

	printf("result is: %d\n", result);
	return 0;
}